[Georgia Tech] [GVU] [Search] [Animation lab]

Deformable Basketball Net

[Basketball: Sim vs. Live]
Closeup and Quicktime page.
Back to Secondary Motion page.

We use a simulation of basketball passing through a deformable basketball net as an illustrative example to demonstrate each of three methods of coupling for simulations. We introduce three different methods for coupling two systems together: two-way, one-way, and hybrid coupled. To clarify the differences between these forms of coupling, we looked at the interaction between the basketball (primary) and the net (secondary) for each form.
[Basketball: Two-way Coupled]
Two-way Coupled (quicktime .7 Mb )

In two-way coupling, the rotational and linear velocity of the ball will respond to the contact with the net and the net will be pushed out of the way by the ball. This results in a realistic interaction between the ball and the net.

[Basketball: One-way Coupled]
One-way Coupled (quicktime .7 Mb )

In one-way coupling, the motion of the ball is not affected by the net and the ball continues on a ballistic trajectory. The deformation of the net will be more extreme than in the two-way coupled case and the motion will not match that of an actual basketball and net as closely.

[Basketball: Hybrid Coupled]
Hybrid Coupled (quicktime .7 Mb )

In between these two solutions are a variety of hybrid coupled solutions where the interaction model is approximated. The results shown here approximate the influence of the net on the ball as a damping field. The ball trajectory is more realistic than in the one-way coupling and still allows the non-parallel processing of the two simulated elements.

Comparison with real life is important as a form of evaluation. Below is a movie file in which the simulated motion and a live basketball shot. The simulation was initialized with conditions similar to the live shot for this comparison.


Quicktime of Simulated and Live Net Comparison (2 Mb)

    Project Members

Questions or comments? Email jkh@cc.gatech.edu